This invention relates to an operation panel device which is suited to an apparatus equipped with a large number of operation switches such as a motor vehicle.
In recent years, a vehicle such as a motor vehicle incorporates various kinds of electric appliances inclusive of a television, navigation system, an audio mechanism such as a CD player, a cassette player, etc. an air conditioner, etc. To this end, various kinds of operation panel devices 8 have been developed in which as seen from FIGS. 12 and 13, a display 1, a CD entrance 2, a cassette entrance 3, a television/navigation operation button 4, an audio operation button 5, an air conditioner operation button 6, indicators 7 are collectively arranged on a center cluster of a dash board.
An operation panel 8a of the operation panel device 8 adopts a number of curved surfaces so that the arrangement and angle of the operation buttons 4, 5 and 6 can have variations taking a design into consideration.
However, since the operation panel 8a of the operation panel device 8 adopts a number of curved surfaces so that the arrangement and angle of the operation buttons 4, 5 and 6 can have variations, it was requested that printed boards on which switches 10 to be operated by the operation buttons 4, 5 and 6 are mounted are arranged divisionally so as to correspond to the positions of the operation buttons 4, 5 and 6 according to the curved surfaces.
Thus, there was necessity of connecting the divided printed boards 11 to one another via connectors or jumper wires. This led to the cost-up.
Each switch 10 was designed as a xe2x80x9crubber contact switchxe2x80x9d to provide tactile feeling when the operation button 4, 5, 6 is pressed. Specifically, as seen from FIGS. 14 to 17, when the operation button 4, 5, 6 is pushed in, an operation shaft 12 of the operation button 4, 5, 6 pushes the switch 10. In this case, the switch 10 is shifted from an initial state as shown in FIG. 15 into a state where a rubber contact 13 is elastically deformed under predetermined force as shown in FIG. 16. Thereafter, as shown in FIG. 17, the rubber contact 13 is abruptly elastically deformed by small operation force. As a result, each switch contact 15 arranged on a switch board 14 is communicated with a contact conductor 16 on the lower surface of the rubber contact 13 so that a predetermined operation signal is produced. Thus, the switch 10 does not almost encounter any operation obstacle while it is shifted from the state of FIG. 16 into the state of FIG. 17, thereby providing the tactile feeling.
Incidentally, in FIG. 14, reference numeral 17 denotes a supporting portion attached to the operation panel 8a. In FIGS. 15 to 17, reference numeral 18 denotes a switch cap, 18 a switch gap, 19 a lower case, and 20 an upper cover.
However, the adoption of the rubber contact switch also led to the cost-up.
Further, in order to disperse light by the printed boards 11, the conventional operation panel device incorporates a plurality of light sources 21 for illuminating the operation buttons 4, 5 and 6 and the indicators on the printed board 11 and also a light guiding plate 22 of acryl resin for guiding the light from the light source 21 to the character or graphic on each of the buttons 4, 5, 6 and another light guiding plate 22 for guiding light to each indicator. In this case, the light guiding plates 22 must be designed so that light with predetermined luminous intensity can be guided. This is troublesome and hence leads to the cost up.
Accordingly, an object of this invention is to provide an operation panel device with freedom of design which can deal with the complicate curved surface of an operation panel at low cost.
The technical means for solving the above problem is an operation panel device equipped with a plurality of operation buttons from each of which the corresponding operation signal is produced according to the operation of each button, characterized in that a string-like resistor body is held in a resistor holding plate, the resistor body having a tube-like elastic outer resistor member, an inner resistor member loosely arranged within the outer resistor member and insulating spacers arranged between the inner resistor member and the outer resistor member at predetermined intervals in the longitudinal direction of the inner resistor member so that the inner periphery of the outer resistor member and outer periphery of the inner resistor member are constantly separated from each other; and a control unit is provided to produce the operation signal, whereby when each operation button is pressed, at the corresponding position, the outer resistor member is elastically deformed to be brought into contact with the inner resistor member so that the control unit decides which operation button is pressed on the basis of the resistance at an individual contact position and produces the corresponding operation signal.
The operation panel device may have a structure in which the resistor holding plate has a groove in which the resistor body is to be firmly positioned.
The operation panel device may have a structure in which a plurality of rubber contacts of an elastic material are arranged so as to correspond to the positions where the outer resistor member is pushed by pressing each the operation buttons, the rubber contacts each including a push-in operation member and a skirt member which is enlarged in the hem toward the outer resistor member.
The operation panel device may have a structure in which a coupling plate is integrally provided to couple the plurality of rubber contacts with one another on the side of their hems.
The operation panel device may have a structure in which the rubber contacts are attached to the resistor holding plate so that the resistor body is held in the groove.
The operation panel device may have a structure in which a light source for illumination is provided within a case of the operation panel device and the resistor holding plate constituting the case is made smooth in the inner surface.
The operation panel device may have a structure in which optical fibers are provided for guiding light to respective indicators of the operation buttons.